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Redefining Death - The Government Redefines Death

brain criteria functions persistent

In 1981 the President's Commission published Defining Death: Medical, Legal and Ethical Issues in the Determination of Death (http://www.bioethics.gov/reports/past_commissions/defining_death.pdf). In its report to President Ronald Reagan and the Congress, the Commission proposed a model statute, the Uniform Determination of Death Act, the guidelines of which would be used to define death:

  • [Determination of Death.] An individual who has sustained either (1) irreversible cessation of circulation and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death must be made in accordance with accepted medical standards.
  • [Uniformity of Construction and Application.] This Act shall be applied and construed to effectuate its general purpose to make uniform the law with respect to the subject of this Act among states enacting it.

Brain Death

The President's Commission incorporated two formulations or concepts of the "whole-brain definition" of death. The Commission stated that these two concepts were "actually mirror images of each other. The Commission has found them to be complementary; together they enrich one's understanding of the 'definition' [of death]."

The first whole-brain formulation states that death occurs when the three major organs—the heart, lungs, and brain—suffer an irreversible functional breakdown. These organs are closely interrelated, so that if one stops functioning permanently, the other two will also stop working. While traditionally the absence of the "vital signs" of respiration and circulation have signified death, this is simply a sign that the brain, the core organ, has permanently ceased to function. Even if individual cells or organs continue to live, the body as a whole cannot survive for long. Therefore, death can be declared even before the whole system shuts down.

The second whole-brain formulation "identifies the functioning of the whole brain as the hallmark of life because the brain is the regulator of the body's integration." Because the brain is the seat of consciousness and the director of all bodily functions, when the brain dies, the person is considered dead.

Reason for Two Definitions of Death

The President's Commission claimed that its aim was to "supplement rather than supplant [take the place of] the existing legal concept." The brain-death criteria were not being introduced to define death in a new way. In most cases the cardiopulmonary definition of death would be sufficient. Only comatose patients on respirators would be diagnosed using the brain-death criteria.

Criteria for Determination of Death

The Commission did not include in the proposed Uniform Determination of Death Act any specific medical criteria for diagnosing brain death. Instead it had a group of medical consultants develop a summary of currently accepted medical practices. The Commission stated that "such criteria—particularly as they relate to diagnosing death on neurological grounds—will be continually revised by the biomedical community in light of clinical experience and new scientific knowledge." These Criteria for Determination of Death read as follows (with medical details omitted here):

  1. An individual with irreversible cessation of circulatory and respiratory functions is dead. A) Cessation is recognized by an appropriate clinical examination. B) Irreversibility is recognized by persistent cessation of functions during an appropriate period of observation and/or trial of therapy.
  2. An individual with irreversible cessation of all functions of the entire brain, including the brainstem, is dead. A) Cessation is recognized when evaluation discloses that cerebral cortical and brainstem functions are absent. B) Irreversibility is recognized when evaluation discloses that: the cause of coma is established and is sufficient to account for the loss of brain functions; the possibility of recovery of any brain functions is excluded; and the cessation of all brain functions persists for an appropriate period of observation and/or trial of therapy.

The Criteria for Determination of Death further warn that conditions such as drug intoxication, metabolic intoxication, and hypothermia may be confused with brain death. Physicians should practice caution when dealing with young children and persons in shock. Infants and young children, who have more resistance to neurological damage, have been known to recover brain functions. Shock victims, on the other hand, might not test well due to a reduction in blood circulation to the brain.

The Brain-Death Concept and Brain-Death Criteria around the World

Since the development of brain-death criteria in the United States, most countries have adopted the brain-death concept. Nevertheless, determining brain death varies worldwide. One reason has to do with cultural or religious beliefs. For example, in Japan it is believed that the soul lingers in the body for some time after death. Such a belief may influence the length of time the patient is observed before making the determination of death.

Eelco F. M. Wijdicks of the Mayo Medical Center in Rochester, Minnesota, surveyed brain-death criteria throughout the world and reported his results in "Brain Death Worldwide: Accepted Fact but No Global Consensus in Diagnostic Criteria" (Neurology, vol. 58, no. 1, January 8, 2002). Wijdicks obtained brain-death guidelines for adults in eighty countries and determined that seventy of the eighty countries had guidelines for clinical practice in determining brain death. In examining these guidelines Wijdicks found major differences in the procedures used for diagnosing brain death in adults. For example, in some countries brain-death criteria are left up to the physician to determine, while in other countries written guidelines are extremely complicated. In some countries confirmatory laboratory tests are mandatory, while in others they are not. Due to these and many other differences in brain-death diagnostic criteria across countries, Wijdicks suggests that countries worldwide consider standardizing procedures to determine brain death.

What are the diagnostic criteria for determining brain death in the United States? In "Variability among Hospital Policies for Determining Brain Death in Adults" (Critical Care Medicine, vol. 32, no. 6, June 2004), David Powner, Michael Hernandez, and Terry Rives explain that there is no federally mandated definition for brain death or method for certifying brain death. Thus, states have adopted the Uniform Determination of Death Act as described in the prior section. Within each hospital, however, actual clinical practice is determined by the medical staff and administrative committees. The researchers studied six hundred randomly selected hospitals to determine whether differences exist among hospital policies for certification of brain death. They determined that differences exist and suggested that policies be standardized. Wijdicks and Ronald E. Cranford list clinical criteria for brain death in "Clinical Diagnosis of Prolonged States of Impaired Consciousness in Adults" (Mayo Clinic Proceedings, vol. 80, no. 8, August 2005). (See Table 2.1.)

Brain Death and Persistent Vegetative State

In the past people who suffered severe head injuries usually died from apnea. Today rapid emergency medical FIGURE 2.1 Parts of the brain "Figure 2. Anatomic Interrelationships of Heart, Lungs, and Brain," in Defining Death: A Report on the Medical, Legal and Ethical Issues in the Determination of Death, President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research, July 1981, http://www.bioethics.gov/reports/past_commissions/defining_death.pdf%20(accessed November 1, 2005)intervention allows them to be placed on respirators before breathing stops. In some cases the primary brain damage may be reversible, and unassisted breathing eventually resumes. In many cases, however, brain damage is irreversible, and, if the respirator is not disconnected, it will continue to pump blood to the dead brain.

TABLE 2.1

Criteria for brain death

Coma

Absence of motor responses

Absence of pupillary responses to light and pupils at midposition with respect to dilatation (4-6 mm)

Absence of corneal reflexes

Absence of caloric responses

Absence of gag reflex

Absence of coughing in response to tracheal suctioning

Absence of respiratory drive at PaCO2 that is 60 mm Hg or 20 mm Hg above normal baseline values

SOURCE: Eelco F.M. Wijdicks and Ronald E. Cranford, "Table 3. Clinical Criteria for Brain Death," in "Clinical Diagnosis of Prolonged States of Impaired Consciousness in Adults," Mayo Clinic Proceedings, vol. 80, no. 8, August 2005

The brain stem, traditionally called the lower brain, is usually more resistant to damage from oxygen deprivation, or anoxia. Less serious brain injury may cause irreversible damage to the cerebrum, or higher brain, but may spare the brain stem. (See Figure 2.1.) When the cerebrum is irreversibly damaged yet the brain stem still functions, the patient goes into a persistent vegetative state (PVS), also called persistent noncognitive state. PVS patients, lacking in the higher-brain functions, are awake but unaware. They swallow, grimace when in pain, yawn, open their eyes, and may even breathe without a respirator. Table 2.2 lists the criteria for the diagnosis of a persistent vegetative state.

TABLE 2.2

Criteria for a persistent vegetative state (PVS)

  1. No evidence of awareness of themselves or their environment; they are incapable of interacting with others
  2. No evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to visual, auditory, tactile, or noxious stimuli
  3. No evidence of language comprehension or expression
  4. Intermittent wakefulness manifested by the presence of sleep-wake cycles
  5. Sufficiently preserved hypothalamic and brainstem autonomic functions to survive if given medical and nursing care
  6. Bowel and bladder incontinence
  7. Variably preserved cranial nerve (pupillary, oculocephalic, corneal, vestibulo-ocular, and gag) and spinal reflexes

SOURCE: Eelco F.M. Wijdicks and Ronald E. Cranford, "Table 1. Criteria for the Diagnosis of a Persistent Vegetative State," in "Clinical Diagnosis of Prolonged States of Impaired Consciousness in Adults," Mayo Clinic Proceedings, vol. 80, no. 8, August 2005

The case of Karen Ann Quinlan called attention to the ramifications of the persistent vegetative state. In 1975 Quinlan suffered a cardiopulmonary arrest after ingesting a combination of alcohol and drugs. In 1976 Joseph Quinlan was granted court permission to discontinue artificial respiration for his comatose daughter. Even after life support was removed, Karen remained in a persistent vegetative state until she died of multiple infections in 1985.

A more recent case that has refocused national attention on the persistent vegetative state is that of Terri Schiavo, who entered a PVS in 1990, when her brain was deprived of oxygen during a heart attack brought on by an eating disorder. Her husband argued that she would never recover and that his wife would not want to be kept alive by artificial means. He petitioned a Florida court to remove her feeding tube. In October 2003 a Florida judge ruled that the tube should be removed. But Schiavo's parents believed that their daughter would recover and requested that Florida Governor Jeb Bush intervene. The Florida legislature subsequently gave Governor Bush the authority to override the courts, and the feeding tube was reinserted six days after its removal.

In May 2004 the law that allowed Governor Bush to intervene in the case was ruled unconstitutional by a Florida appeals court. The case was then appealed to the U.S. Supreme Court, which in January 2005 refused to hear the appeal and reinstate the Florida law. In March 2005 doctors removed Terri Schiavo's feeding tube. She died thirteen days later. An autopsy showed extensive damage throughout the cerebrum. Damage was so severe that the autopsy report noted that Schiavo must have been blind.

Patients in a persistent vegetative state are not dead, and so the brain-death criteria do not apply to them. They can survive for years with artificial feeding and antibiotics for possible infections. The President's Commission reported on a patient who remained in a persistent vegetative state for thirty-seven years: Elaine Esposito, who lapsed into a coma after surgery in 1941 and died in 1978.

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